What should I pick... The Geforce4 ti4200 64 mb... or 128 mb version... The 64 version has a higher clockspeed and memory bandwidth. But of course the 128 has more memory. Arg!!!!!!! What to choose????

I'd pick the 128MB version. Demos of newer games or game engines (like Comanche or Code Creatures) seem to do better with more memory. The performance penalties for a slightly slower clock speed (on the 128MB version) won't be nearly as severe as the penalties for not having enough local video memory (on the 64MB cards).

I've pretty much decided on the 128MB as the 64MB will o/c MUCH better but you can't ever add another 64MB RAM. The older games will benefit with AA and the newer ones will simply req more than 64MB to get the best perf.

Either way WE'll be getting better perf than the GF3TI500 and Radeon 8500 (both mostly 64MB) which were £300 only 2 months ago!